Lifting mechanism and key structure using the same
A key structure is provided. The key structure includes a base plate, a key cap and a lifting mechanism is provided. The base plate includes a first bottom wall. The key cap is disposed opposite to the base plate and includes a first cap wall. The lifting mechanism is movably connected between the key cap and the base plate, so that the key cap could reciprocate with respect to the base plate. The lifting mechanism includes a first lower shaft portion and a first upper shaft portion, which are respectively movably connected on the same side of the key cap and the base plate. When the key cap is in a released state, the first upper shaft portion presses against the first cap wall, but the first lower shaft portion is separated from the bottom wall by a maintaining gap.
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This application claims the benefit of Taiwan application Serial No. 110113646, filed Apr. 15, 2021, the subject matter of which is incorporated herein by reference.
BACKGROUND OF THE INVENTION Field of the InventionThe invention relates in general to a lifting mechanism and a key structure using the same, and more particularly to a lifting mechanism whose lower shaft portion is separated from a bottom wall of a base plate by a maintaining gap and a key structure using the same.
Description of the Related ArtA conventional key structure includes a key cap, a lifting mechanism and a base plate. To adopt an automated assembly, the lifting mechanism must first be assembled and connected to the base plate, and then the key cap assembly is connected to the lifting mechanism on the base plate, so that the lifting mechanism could be connected to the key cap and the base plate. However, after several years of thinning trend in electronic devices, the size of the connection parts between the key cap, the lifting mechanism and the base plate could be reduced no more. Moreover, the automated assembly of the lifting mechanism relates to many design requirements and complicated factors. For example, the height control of the key cap needs to be accurate and precise, the upward/downward lifting of the key cap must not be skewed, pullout resistance needs to be provided between the lifting mechanism and the base plate, the lifting mechanism cannot be detached, and the structure of the lifting mechanism cannot be damaged or deformed. These design requirements and factors affect the structural strength and operation of the key as well as the actions, procedures, schedules and capacity of the automated assembly. Particularly, the abrasion loss generated between the lifting mechanism and the base plate during the assembly process will change the predetermined lifting stroke of the key structure, making the height control of the key inaccurate. Therefore, it has become a prominent task for the industries to provide a key structure, which has suitable design and is capable of resolving the above problems encountered in the prior art.
SUMMARY OF THE INVENTIONThe invention is directed to a key structure capable of resolving the problems encountered in the prior art.
According to one embodiment of the present invention, a key structure is provided. The key structure includes a base plate, a key cap and a lifting mechanism is provided. The base plate includes a first bottom wall. The key cap is disposed opposite to the base plate and includes a first cap wall. The lifting mechanism is movably connected between the key cap and the base plate, so that the key cap could reciprocate with respect to the base plate. The lifting mechanism includes a first lower shaft portion and a first upper shaft portion, which are respectively movably connected on the same side of the key cap and the base plate. When the key cap is in a released state, the first upper shaft portion presses against the first cap wall, but the first lower shaft portion is separated from the bottom wall by a maintaining gap.
According to another embodiment of the present invention, a lifting mechanism is provided. The lifting mechanism is movably connected between a key cap and a base plate, so that the key cap could reciprocate with respect to the base plate. The lifting mechanism includes a pair of brackets relatively movable to each other. The pair of brackets includes a first upper shaft portion and a first lower shaft portion, which are respectively movably connected on the same side of the key cap and the base plate. When the key cap is in a released state, the first upper shaft portion presses against a first cap wall of the key cap, but the first lower shaft portion is separated from a first bottom wall of the base plate by a maintaining gap.
The above and other aspects of the invention will become better understood with regard to the following detailed description of the preferred but non-limiting embodiment (s). The following description is made with reference to the accompanying drawings.
Refer to
As indicated in
Each embodiment of the present invention mainly relates to the adjustment of the height control structure of the key cap 120. The height of the key cap refers to the height of the key cap 120 at the highest position relative to the base plate 110 when the key structure 100 and the key cap 120 are in a released state. The so called “height control” refers to redesigning the element structure of the key structure 100 to control the highest position of the key cap 120 during the lifting stroke. When the key cap 120 reaches the highest position, the scissor-type lifting mechanism 130 is also expanded to reach the highest point. Nonetheless, due to the design complexity, it is very important to understand the inventive ideas of the embodiment of the present invention.
Firstly, the base plate 110 processed with metal machining has higher precision and accuracy, and the connection parts of the base plate 110 are generally used in the design of a height control mechanism. Moreover, when the key cap 120 changes to the pressed state from the released state, the two interconnected brackets of the scissor-type lifting mechanism 130 (the two interconnected brackets respectively are outer bracket 130X and inner bracket 130Y) ensure that the key cap 120 could be stably lifted upwards and downwards. The connection parts between the base plate 110 and the key cap 120 need to firmly grasp the shaft of the lifting mechanism 130 (the shaft is such as the second lower shaft portion 131B, the first lower shaft portion 131A, the first upper shaft portion 132A and the second upper shaft portion 132B) to avoid the shaft coming off the lifting mechanism 130 and also assure that the shaft of the lifting mechanism 130 has sufficient allowance for rotation and/or translation during the lifting stroke. In the automatic assembly process, to increase the bonding strength between the lifting mechanism 130 and the key cap 120 and the base plate 110 respectively, reduce the assembly gap, and increase the assembly speed, assembly interference could be prioritized. However, assembly interference also makes the plastic brackets 130X and 130Y being cut and damaged by the edge of the connection parts of the metal base plate 110 and form a new element gap. Thus, to implement the height control mechanism using the connection parts of the base plate 110 according to the prior art, the problem of element gap being generated on the base plate 110 must be resolved together.
In view of the cross-sectional view, such as
According to the embodiment of the present invention, the sliding side of two junctions through which the lifting mechanism 130 and the key cap 120 are connected is selected as the target structure of height control, so that factors such as assembly interference, element damage and element gap will not cause unnecessary interference to height control, and the problem of inaccurate height control caused by assembly interference, element damage and element gap will be resolved.
As indicated in
The key cap 120 further includes at least a pair of second cap walls 122. The second upper shaft portion 132B of the lifting mechanism 130 is located on the other side of the inner bracket 130Y (the second side S2) opposite to the first lower shaft portion 131A; the second upper shaft portion 132B is clamped by two second cap walls 122 to be pivotally connected to the key cap 120, so that the second upper shaft portion 132B becomes the rotation side of the lifting mechanism 130 in the direction of the key cap 120. The base plate 110 further includes one or more second bottom walls 112 (
During the assembly process of the base plate 110 and the lifting mechanism 130, the second lower shaft portion 131B of the lifting mechanism 130 is firstly bucked to the second bottom wall 112 of the base plate 110, then the lifting mechanism 130 rotates around the second bottom wall 112 until the first lower shaft portion 131A is buckled to the first bottom wall 111. In an embodiment, the hardness of the first bottom wall 111 is greater than the hardness of the first lower shaft portion 131A of the lifting mechanism 130. In terms of material, the base plate 110 is made of metal such as stainless steel or alloy; the lifting mechanism 130 is formed of polymer such as plastics or synthetic resin. Since the hardness of the first bottom wall 111 is greater than the hardness of the first lower shaft portion 131A, during the buckling process of the first lower shaft portion 131A and the first bottom wall 111, the side of the first lower shaft portion 131A facing the lateral hook segment 111h of the first bottom wall 111 will have an abrasion loss w. According to the embodiment of the present invention, the first lower shaft portion 131A and the first bottom wall 111 in a released state are separated from each other (do not press each other), therefore the abrasion loss w does not affect the lifting stroke of the key cap 120. Certainly, the lifting mechanism 130 could adopt vertical assembly. When the second lower shaft portion 131B is buckled to the second bottom wall 112 of the base plate 110, the first lower shaft portion 131A will also have abrasion loss w when interfering with the assembly of the lateral hook segment 111h of the first bottom wall 111.
The height control mechanism of the key cap 120 mainly relates to the connection parts connecting the lifting mechanism 130 to the key cap 120 and the base plate 110. Refer to
Refer to
When the key cap 120 is in a released state (as indicated in
Although the plastic key cap 120 is normally formed using a mold and will generate a certain amount of tolerance d, the tolerance d does not affect the abovementioned height control of the key cap. As indicated in
In an embodiment, the first upper shaft portion 132A of the lifting mechanism 130 and the first cap wall 121 of the key cap 120 are formed of the same material, such as polymer like plastics. Since the first upper shaft portion 132A and the first cap wall 121 are formed of the same material, when the first upper shaft portion 132A is bucked to the first cap wall 121, the first upper shaft portion 132A and the first cap wall 121 are merely deformed and generate no abrasion or only a slight abrasion loss. This slight abrasion loss (if any) is unable to change the lifting stroke of the key cap 120.
In above embodiments as indicated in
Although in the above embodiments, the first upper shaft portion 132A of the outer bracket 130X and the first cap wall 121, the first lower shaft portion 131A of the inner bracket 130Y and the first bottom wall 111 are used as sliding sides, in other embodiments the arrangement could be reversed. That is, the first upper shaft portion could belong to the end of the inner bracket close to the key cap, the first cap wall could also belong to the first upper shaft portion of the key cap corresponding to the inner bracket. Similarly, the first lower shaft portion could belong to the end of the outer bracket close to the base plate, and the first bottom wall also could belong to the first lower shaft portion of the base plate corresponding to the outer bracket. That is, in terms of the scissor-type lifting mechanism, as long as a pair of sliding sides is arranged on the same side, and the sliding side of the key cap is used in the height control mechanism, desired effects of the inventive ideas of the present invention will be achieved.
To summarize, a key structure is provided according to the embodiment of the present invention. The key structure includes a key cap, a lifting mechanism and a base plate. When the key cap is in a released state, the lower shaft portion of the lifting mechanism is separated from the bottom wall of the base plate by a maintaining gap. Thus, even when the lower shaft portion has an abrasion loss, the abrasion loss will not affect the predetermined lifting stroke of the key cap and the height of the key because the lower shaft portion and the bottom wall in a released state are separated from each other. Therefore, the key structure of the embodiment of the present invention particularly meets the design requirements of the thinned key with a shorter stroke.
While the invention has been described by way of example and in terms of the preferred embodiment(s), it is to be understood that the invention is not limited thereto. On the contrary, it is intended to cover various modifications and similar arrangements and procedures, and the scope of the appended claims therefore should be accorded the broadest interpretation so as to encompass all such modifications and similar arrangements and procedures.
Claims
1. A key structure, comprising: a base plate comprising a first bottom wall; a key cap disposed opposite to the base plate and comprising a first cap wall; a lifting mechanism movably connected between the key cap and the base plate, so that the key cap reciprocates with respect to the base plate, wherein the lifting mechanism comprises a first lower shaft portion and a first upper shaft portion which are respectively movably connected on the same side of the base plate and the key cap; wherein when the key cap is in a released state, the first upper shaft portion presses against the first cap wall, but the first lower shaft portion is separated from the first bottom wall by a maintaining gap; wherein in a pressed state, the first lower shaft portion is separated from the first bottom wall by a bottom wall gap, the first upper shaft portion is separated from the first cap wall by a cap wall gap, and the cap wall gap is smaller than the bottom wall gap.
2. The key structure according to claim 1, wherein the lifting mechanism comprises an inner lateral arm and an outer lateral arm which are pivotally connected in a pivotal direction; the first lower shaft portion and the first upper shaft portion are located on the same side of the pivotal direction.
3. The key structure according to claim 1, wherein the first bottom wall of the base plate has a hardness greater than that of the first lower shaft portion of the lifting mechanism.
4. The key structure according to claim 1, wherein the first upper shaft portion of the lifting mechanism and the first cap wall of the key cap both are formed of polymer.
5. The key structure according to claim 1, wherein a surface of the first lower shaft portion facing the first bottom wall has an abrasion loss, and the maintaining gap is greater than the abrasion loss.
6. The key structure according to claim 1, wherein the key cap further comprises a second cap wall, and an absolute value of a tolerance of a difference between the first cap wall and the second cap wall is smaller than the maintaining gap.
7. A lifting mechanism movably connected between a key cap and a base plate, so that the key cap reciprocates with respect to the base plate, wherein the lifting mechanism comprises: a pair of brackets relatively movable to each other, wherein the pair of brackets comprises a first upper shaft portion and a first lower shaft portion which are respectively movably connected on the same side of the key cap and the base plate; wherein when the key cap is in a released state, the first upper shaft portion presses against a first cap wall of the key cap, but the first lower shaft portion is separated from a first bottom wall of the base plate by a maintaining gap; wherein in a pressed state, the first lower shaft portion is separated from the bottom wall by a bottom wall gap, the first upper shaft portion is separated from the first cap wall by a cap wall gap, and the cap wall gap is smaller than the bottom wall gap.
8. The lifting mechanism according to claim 7, wherein the pair of brackets is pivotally connected to each other.
9. The lifting mechanism according to claim 7, wherein the first upper shaft portion and the first lower shaft portion are respectively movably connected on a first side of the key cap and the base plate; the pair of brackets further comprises a second upper shaft portion and a second lower shaft portion which are respectively pivotally connected on a second side of the key cap and the base plate, and the second side is opposite to the first side.
10. The lifting mechanism according to claim 7, wherein the pair of brackets comprises an inner lateral arm and an outer lateral arm which are pivotally connected in a pivotal direction, and the first lower shaft portion and the first upper shaft portion are located on the same side of the pivotal direction.
11. The lifting mechanism according to claim 10, wherein the pair of brackets further comprises a second upper shaft portion and a second lower shaft portion which are located on a side opposite to the same side of the pivotal direction.
12. The lifting mechanism according to claim 7, wherein a surface of the first lower shaft portion facing the first bottom wall has an abrasion loss, and the maintaining gap is greater than the abrasion loss.
13. The key structure according to claim 7, wherein the key cap further comprises a second cap wall, and an absolute value of a tolerance of the difference between the first cap wall and the second cap wall is smaller than the maintaining gap.
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- Office action of counterpart application by Taiwan IP Office dated Nov. 25, 2021.
Type: Grant
Filed: Apr 11, 2022
Date of Patent: Mar 14, 2023
Patent Publication Number: 20220336165
Assignee: Darfon Electronics Corp. (Taoyuan)
Inventors: Po-Chun Hou (Taoyuan), Chin-Hung Lin (Taoyuan)
Primary Examiner: Ahmed M Saeed
Application Number: 17/717,287
International Classification: H01H 3/12 (20060101); H01H 13/14 (20060101); H01H 13/10 (20060101); H01H 13/20 (20060101);